Installing replacement windows is an important step towards improving the look of your home, increasing the energy efficiency and helping to protect your family. Even with all of the benefits, many homeowners are reluctant to replace their windows due to the cost of both buying and installing their replacement windows.

One way to lower the price is with do it yourself window installation. While this is certainly not recommended for everyone, it is nontheless an option for those who are competent with home improvement projects. The one basic rule of thumb for DIYers is this: as long as the replacement windows will "reasonably" fit into the existing frames (meaning that no extensive frame work is required), you can try and tackle this project.

We will breakdown all the tools you will need for the job, the steps you will take to prep the job, a step-by-step guide to installation and a helpful tips section. We hope you enjoy our do it yourself window replacement guide.

Tools For DIY Window Replacement

Replacement windows are much different than 'new construction' windows. New construction windows require alterations to the trim and sometimes other parts of the wall because they include the frame as well as the window. In fact, new construction windows require a homeowner to actually remove the outside trim completely due to the nailing flange around the window frame. Replacement windows, on the other hand, are installed from the inside. No need to remove any exterior trim or stucco!

Here are the tools you'll need to tackle a replacement window project:

Tape measure

Pry bar

Chisel or ice pick

Utility knife

Level

Drop cloths

Reciprocating saw

Replacement windows

Caulking gun and caulk, shims (small wedges)

Hammer, nail set and finishing nails (1 1/2)

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Prepping For The Project

Step 1 - The very first step is to determine the style and material you want for your new windows. You can replace your windows with practically any style (casement, double hung, etc.) of window; you don't have to stick with what you have. (Remember, though, that bow and bay windows generally require more structural modifications and would be more like a new construction window.) Replacement windows are available in vinyl, wood, clad wood, or composite, as well as aluminum.

Step 2 - Examine your sills. Make sure there's no wood rot. If the frame is compromised, it doesn't make any sense to install replacement windows.

Step 3 - This is the most important step: measuring your windows. You have to get this right, or you'll be buying windows you can't use, and that's an expensive mistake. First, measure the height and width of your existing windows. Get multiple measurements to be precise. For each window, measure the width from jamb to jamb (side to side) at the top, middle and bottom of the window. Then measure the height from the sill to the top of the window at the left, center, and right side. Use the smallest measurements to ensure your replacement window fits properly.

Step 5 - Let the installation begin! Start by removing the inside stops on your windows. Save them; you can use them again when you install the replacement window.

Step 6 - Take out the sashes and clean up the frame. If you have to, cut through any nails that might be holding the sashes in. Remove the old caulk and either drive in or remove remaining nails.

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Installing Replacement Windows

Now comes the fun part:

Step 1 - Before doing anything, make sure the window you ordered will actually fit into the opening. Place it into the frame and check the fit.

Step 2 - Caulk the inside edge of the outside window stops, and along the windowsill. Just a thin bead of caulking will do.

Step 3 - Put the window in the center of the frame. Use your level to make sure it's plumb and square (measure diagonally from corner to corner, both ways, to check that it's square). Shim the window to keep it in place while you grab your gear.

Step 4 - Take the inside stops you saved from your old windows (you kept them, right?) and reinstall them in the new windows. Use 1 1/2-inch finishing nails, and be sure to set the nails.

Step 5 - Where the stops meet the frame, caulk.

Step 6 - Go outside and examine your handiwork. The window should have a sloped frame that matches the slope of the sill. If not, it should come with an insert that can be used to cover the gap. If there's a gap but you don't have an insert, you can cover it with a piece of wood. Caulk the seams where the insert (or your piece of wood) goes against the frame.

Step 7 - Relax. You're done!

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Helpful Tips For A Successful DIY Window Project

* Measure carefully! Did we mention how important measuring was? Take at least three measurements, width and height, for each window. Your replacement window has to fit inside the existing frame, so take the smallest of the three width and height measurements.

* Some window pros recommend taking an extra 1/4-inch off the smallest measurement, just to be extra careful. Remember, you can always caulk and shim to fill gaps, but if the window you order is too large, you're out of luck (and money).

* Double-check your new windows when they arrive. Are they exactly what you ordered? Best to catch any mistakes now rather than in the middle of an install.

* When testing your sills for rot, use an ice pick, awl, or small chisel to see if the wood is sound.

* Don't be alarmed if you notice your windows seem smaller. As replacement windows have to fit into an existing frame, they are smaller than your current windows. If this isn't a sacrifice you're willing to make, then you will have to investigate the option of new construction windows. New construction windows are more expensive, however.